1. Field
The present disclosure relates generally to aircraft and, in particular, to a method and apparatus for detecting skew in slats on an aircraft.
2. Background
Flight control surfaces on an aircraft are used to maneuver and control the altitude of an aircraft. An aircraft may have many types of flight control surfaces. These flight control surfaces include, for example, ailerons, elevators, rudders, spoilers, flaps, slats, airbrakes, and/or other suitable control surfaces.
Slats are located on the leading edges of wings on a fixed-wing aircraft. Slats allow a wing to operate at a higher angle of attack when the slats are deployed as compared to when they are not deployed or used. An aircraft typically has multiple slats on each wing.
Each slat is typically driven between an extended and a retracted position using an actuator system. The movement of the slats is typically performed such that the slats are aligned. In other words, the slats may be moved such that they are substantially aligned along an axis.
A jam, a disconnect, and/or some other situation may cause one or more of the slats to fail to move in a manner that maintains alignment along an axis with the other slats. This misalignment in the slats may be referred to as skew. The amount of skew that is present may affect the aerodynamics of the aircraft. For example, if the degree of skew of one slat relative to the other slats is greater than some amount, the angle of attack that can be maintained for a wing at a given airspeed without stalling can change.
Skew detection systems are used on aircraft to detect skew in slats such that alerts may be generated and/or actions can be taken in case an undesired amount of skew occurs. Different types of skew detection systems are presently used on aircraft. For example, in one system, a long lanyard and sensor switch mechanism is employed. The lanyard spans the interfaces of the slats. Another slat skew detection system provides a sensor at the interface of each slat. The sensor detects relative motion between the two slats. In yet another skew detection system, a line is employed that passes through the slats with a cutting device. The cutting device cuts the line if the slats become skewed beyond some desired amount.
The different slat skew detection systems that are currently available may be more complex than desired. Some slat skew detection systems may increase the weight and complexity beyond desired levels. Further, the amount of skew detected by different systems may not provide the flexibility desired.
Therefore, the different advantageous embodiments recognize that it would be advantageous to have a method and apparatus that takes into account one or more of the issues described above, as well as possibly other issues.